Zhao Yubo, Feng Yi, Wu Liang
The Key Laboratory of Biomedical Information Engineering of Ministry of Education Department of Biomedical Engineering School of Life Science and Technology Xi'an Jiaotong University Xi'an People's Republic of China.
The Key Laboratory of Biomedical Information Engineering of Ministry of Education Department of Biomedical Engineering School of Life Science and Technology Xi'an Jiaotong University Xi'an People's Republic of China.
Ultrason Sonochem. 2025 Feb;113:107234. doi: 10.1016/j.ultsonch.2025.107234. Epub 2025 Jan 20.
Acoustic droplet vaporization (ADV) plays a crucial role in ultrasound-related biomedical applications. While previous models have examined the stages of nucleation, growth, and oscillation in isolation, which may limit their ability to fully describe the entire ADV process. To address this, our study developed an integrated model that unifies these three stages of ADV, stimulated by a continuous nonlinear dual-frequency ultrasound wave. Using this integrated model, we investigated the influence of nonlinear dual-frequency ultrasound parameters on ADV dynamics and bioeffects by incorporating tissue viscoelasticity through parametric studies. Our results demonstrated that the proposed model accurately captured the entire ADV process, ensuring continuous vapor bubble formation and evolution throughout the phase transition process. Moreover, the applied unified theory for bubble dynamics can simulate intense bubble collapse with high Mach Number as a result of the nonlinear effects of dual-frequency ultrasound. In addition, cavitation-associated mechanical and thermal damage appeared to be more strongly correlated with rapid bubble collapse than with maximum bubble size. Our research also revealed that the mechanical and thermal effects could be regulated independently to some extent by adjusting dual-frequency ultrasound parameters, as they presented differing sensitivities to frequency and acoustic power. Importantly, dual-frequency combinations such as 1.5 MHz + 3 MHz (fundamental and second harmonic), which exhibit a higher Degree of Nonlinearity (DoN) can extend bubble lifespan, offering a potential pathway to the efficacy of ultrasound treatments.
声滴汽化(ADV)在超声相关的生物医学应用中起着至关重要的作用。虽然先前的模型已经分别研究了成核、生长和振荡阶段,但这可能会限制它们全面描述整个ADV过程的能力。为了解决这个问题,我们的研究开发了一个集成模型,该模型由连续的非线性双频超声波激发,将ADV的这三个阶段统一起来。利用这个集成模型,我们通过参数研究将组织粘弹性纳入其中,研究了非线性双频超声参数对ADV动力学和生物效应的影响。我们的结果表明,所提出的模型准确地捕捉到了整个ADV过程,确保了在整个相变过程中持续形成和演化蒸汽泡。此外,由于双频超声的非线性效应,应用的气泡动力学统一理论可以模拟高马赫数下强烈的气泡坍塌。此外,与空化相关的机械和热损伤似乎与快速气泡坍塌的相关性比与最大气泡尺寸的相关性更强。我们的研究还表明,通过调整双频超声参数,机械和热效应在一定程度上可以独立调节,因为它们对频率和声功率表现出不同的敏感性。重要的是,诸如1.5MHz + 3MHz(基波和二次谐波)等具有较高非线性度(DoN)的双频组合可以延长气泡寿命,为超声治疗的疗效提供了一条潜在途径。